Inspection apparatus

Abstract

An inspection apparatus for determining the contours of sheet material, particularly glass sheets, comprising a checking fixture having a plurality of probe assemblies for determining the exact position of points along the sheet and the deviation, if any, of such measured points from reference points constituting the ideal contour. The probe assemblies generate linear signals transmitted to a controller which, in turn, converts such signals into data displayed on a video screen in selectively different forms.

We claim: 
     
       1. A probe assembly for use in a sheet contour inspecting apparatus comprising: an elongated body having at one end thereof a head portion provided with an axial bore therethrough, a removable probe disposed in said bore for axial movement therein, said probe having a sensing head at one end thereof protruding outwardly of said bore and engageable with a sheet to be checked, electric means releasably secured within said body for sensing the position of said probe and including means for generating an electrical signal proportionate to the axial position of said probe, said body having a cut-out section intermediate the opposite ends thereof for providing access to said sensing means, said sensing means including a reciprocal plunger coaxially aligned with said probe and engageable at one end thereof with the other end of said probe for movement, as a unit, therewith, a movable piston mounted within said body adjacent the other end thereof, the other end of said plunger extending into said piston, said piston being formed with a slot permitting lateral withdrawal of said plunger other end from said piston when withdrawing said sensing means through said cut-out section for easy removal and replacement. 
     
     
       2. A probe assembly according to claim 1, wherein said body other end is provided with an inlet for connection to a supply of fluid under pressure. 
     
     
       3. A probe assembly according to claim 1, wherein said plunger is provided with an enlarged formation at said other end thereof and said piston is formed with a second slot formation receiving said plunger enlarged formation. 
     
     
       4. A probe assembly according to claim 1, including means for limiting axial movement of said probe within said bore. 
     
     
       5. A probe assembly according to claim 1, wherein said sensing means comprises a linear potentiometer. 
     
     
       6. A probe assembly according to claim 1, in combination with control means for converting said signal into display indicia commensurate with the magnitude of said signal. 
     
     
       7. The combination according to claim 6, wherein said control means includes means for selectively displaying said indicia in different selective forms. 
     
     
       8. A plurality of probe assemblies according to claim 1, in combination with a contour checking fixture comprising a base member having a top wall provided with a contoured surface conforming to the ideal contour desired, and a plurality of spaced openings in said top wall and said contoured surface for accommodating said probe assemblies, respectively. 
     
     
       9. The combination according to claim 8, including an insert fitted into each of said top wall openings and having a threaded bore therethrough, said body head portion having an arcuate segment formed with threads engageable with the threads of said insert bore for selective axial positioning of said body within said insert. 
     
     
       10. The combination according to claim 9, including means securing said body in a selected axial position within said insert. 
     
     
       11. Apparatus for checking the contour of sheet material comprising: a fixture having a rail formed with a contoured surface conforming to the ideal contour desired, a plurality of spaced probe assemblies mounted on said fixture, each of said assemblies having a probe extensible through an opening in said contoured surface for engagement with a sheet, means for supporting said sheet above said contoured surface, means responsive to the placement of a sheet on said supporting means for lowering the same to deposit said sheet on said contoured surface, means for moving said probes into contact with said sheet, said probe assemblies including electrical sensing means for generating electrical signals corresponding to the positions of the associated probes thereof, each said probe assembly having a body housing said probe and said sensing means and formed with a cut-out section providing access to said sensing means for lateral withdrawal thereof from said body through said cut-out section for easy removal and replacement, and control means converting said several electrical signals of said probe assemblies into display indicia commensurate with the magnitudes of said signals. 
     
     
       12. Apparatus according to claim 11, wherein said control means includes means for selectively displaying said indicia in different selective forms. 
     
     
       13. Apparatus according to claim 11, wherein said sensing means are adapted to generate a first series of electrical signals corresponding to the positions of said probes when engageable with a master sheet positioned on said contoured surface to simultaneously establish reference positions for said probes. 
     
     
       14. Apparatus according to claim 13, wherein said sensing means are adapted to generate a second series of electrical signals corresponding to other positions of said probes when engageable with a sheet to be checked positioned on said surface for comparison with said first series of electrical signals to determine the deviation between said reference positions and said other positions. 
     
     
       15. Apparatus according to claim 14, wherein said control means converts said first and second series of electrical signals into display indicia commensurate with the magnitude of said signals, respectively. 
     
     
       16. Apparatus according to claim 15, wherein said indicia is in the form of numerical characters. 
     
     
       17. Apparatus according to claim 15, wherein said indicia is in the form of graphic representations. 
     
     
       18. Apparatus according to claim 15, wherein said control means is operable to display indicia in the form of a graphic representation of the contour of the sheet being checked relative to the graphic representation of a contour trend established for a given number of previously checked sheets. 
     
     
       19. Apparatus according to claim 11, wherein said sensing means of each of said probe assemblies includes a reciprocal plunger coaxially aligned with said probe and engageable therewith for movement, as a unit, with said probe. 
     
     
       20. Apparatus according to claim 11, wherein each of said probe assemblies includes an elongated body releasably secured on said fixture, said probe and said sensing means of each probe assembly being removably mounted within said body.